Direct vent furnace issue...

[3pronghook]

new longvie 18,000 btu direct vent furnace in my wheelhouse has an attitude. it seems that no matter which way the wind is from i have problems with the flame. It will at times dance and stay off the thermocouple for 4-5 seconds and then it shuts off. Like it is supposed too. Always relights, but i have had to tape some cardboard over the top or on side to keep it from happening. i see alot of these dv furnaces on wheelhouses and other perm shacks. is there something i need to add to the vent to keep this from happening? any recommendations about what i can do to keep this from happening?

[Eric Wettschreck]

Do you have some type of mushroom cap over the exterior furnace vent? If not that is likely the problem.

[cold one sd]

I have heard that if your vent goes out the back of your heater and through the wall your vent pipe has length limits that you have to follow. I think on my Empire I need to have 4 1/2" of space between the back of the heater to the outside vent. I know thqre are guys on here that have installed them and are more knowledgable than I am. Does yours vent out through the wall???

[3pronghook]

It does vent out the wall. I dont have a mushroom cap on it and that is what i was thinking it might need. Something that is larger diameter than the pipe to fit on the end of the vent? I have seen rain caps and will keep looking for other options.

[lives.4.fishing]

I am also having some trouble with my DV heater. I have a homecomfort 18,000 btu and we are using 20lb tanks (which might be part of the problem), the other night we had a full tank hooked up, it would light up and the pilot would stay lit but when I would turn it up, it would go out. But if you went back to pilot, you could get it to light again but it would go out again when I turned it up. It was super cold out, -25, do I need a bigger tank or is there something else going on, or was it so cold that something froze up?

Any help would be greatly appreciated

Thanks

[Bigsmitty]

You could try turning the pilot flame up. Look for a little brass screw on the face of the valve and turn it counter clockwise. If that doesnt help you could make a wind shield. We have done that with good success. What we did is take a piece of tin flashing and bend it in a U shape a little larger then the vent termination. Then screw it to the siding with the open ends up and down. This will let the unit breath but wont allow the wind to blow out the pilot flame.

[lives.4.fishing]

Thanks I will see if that works, but I don't think the problem is with the pilot light being blown out by wind coming in through the vent. It seam like it has more to do with lack of pressure or a faulty unit because that night it wasn't windy at all but cold as he#@, -25.

Do you know if a bigger tank is needed for these type of heaters? like a 40 pounder... I'm only using a 20lb and when its not a full tank or say 3/4 full is when the problems seam to start.

[blue_healer_guy]

If you read your manuals it will say not to use unless "so" many pound tank. Thats more likely your problem.

[fishinalot]

Sounds like a draft problem. If you don't have at least 3" or more of wall, you should add a vent box extension to keep down the draft. The longer the vent pipe, the better.

[ice_it_06]

After all my issues with my heater going out I thought of the "draft" possibility after I tore the thing out. Mine is vented through the wall with about a 2' section of pipe before it enters the wall. Outside it travels up the side of the house 8' and another 18" past the roof top.

Mine has a umbrella/mushroom cap on it.

Took my heater in for service and hope it wasn't unwarranted now.

It's a old Dearborn lp furnace which there doesn't seem to be to many familiar with them but were rather popular I hear years ago.

Hopeful its just a tune-up fix as parts might be impossible which means a $400+ vented heater bill for a new one.